The present invention relates to aquariums, typically of a size that would be used in a residence or business rather than a commercial aquarium, and that are intended to provide an appropriate environment, potentially including salt water, in which small jellyfish and similar organisms can survive for extended periods.
The growth in the number and sophistication of municipal and state aquariums is at least one factor in the increased interest in smaller saltwater aquariums; e.g. for personal or business use rather than as public facilities. In turn, jellyfish represent a species that has gained interest because of their motion, appearance, and somewhat exotic nature.
Jellyfish are, however, delicate creatures of which only a very small amount (typically about 5%) is solid organic matter. Jellyfish are technically a form of plankton, are invertebrates, and lack any brain or specialized systems of digestion or circulation. Jellyfish have a limited nervous system that reacts to selected external stimuli.
Jellyfish depend entirely on factors other than themselves for horizontal movement; e.g., in nature winds, tides, and currents. Most jellyfish are, however, capable of some form of vertical motion and can orient themselves based upon their perception of light.
In an aquarium environment jellyfish cannot generally be maintained in a rectangular tank because they are likely to become stuck in, or injure themselves at, corners or similar spaces. Accordingly, a jellyfish aquarium (sometimes referred to as a kreisel tank) whether large or small typically has curved or circular geometry, and is designed to replicate (or at least appropriately mimic) ocean currents or similar movement that keep jellyfish suspended in water while maintaining their equilibrium and natural shape.
In such an aquarium, the water must move sufficiently to keep the jellyfish suspended and gently moving, but less than would injure the jellyfish or force them against the walls too aggressively. Furthermore, any pumps or other mechanical means for moving the water must avoid injuring or capturing the jellyfish. Because of their extremely low mass and fragile structure, jellyfish are easily drawn towards such outlets where they can become injured or die. Additionally, many jellyfish cannot tolerate air bubbles and thus any water-air mixtures or mixing devices (e.g., airstones) should be segregated from the jellyfish.
From a filtration standpoint, a jellyfish aquarium must provide both the desired saltwater environment and means for removing waste materials produced by the jellyfish or that are byproducts of the other aquarium functions. In most aquariums, such materials will include ammonia and similar compounds produced from the ongoing biological processes. These compositions will at some point become disadvantageous or hazardous to the jellyfish. A typical jellyfish aquarium should also have a surface skimming capability and a filtration capability. Some (but not all) jellyfish need to be maintained at or near colder ocean temperatures. In such cases, water temperature should also be maintained at or near 55-65° F. in order to mimic the ocean environment. For such jellyfish, an aquarium typically includes a cooling system of some type (refrigeration unit; chiller).
Because jellyfish are so fragile, such cooling and filtration systems are typically maintained separately from the aquarium tank itself and some piping and appropriate systems must be included to remove water from the aquarium, clean and chill the water, and return it to the aquarium tank; e.g., U.S. Pat. No. 7,610,878.